You know those cat pictures you keep sharing on social media sites? They may reveal more about you than your love of felines.
Florida State University Assistant Professor Owen Mundy recently launched the website, IKnowWhereYourCatLives.com. Mundy's "data experiment" examined one million public photos of kitties and, using the latitude and longitude coordinates embedded in the photos' EXIF metadata, pinpointed the images on a world map. You can read about Mundy's methodology in a blog post on his site.
Mundy says his project exposes "the status quo of personal data usage by startups and international megacorps who are riding the wave of decreased privacy for all."
I applaud Mundy's creative attempt to raise the privacy red flag. The real question: How can you avoid disclosing location info when sharing photos? The question is particularly relevant because many of us take pictures with our iOS and Android phones and directly upload them, EXIF metadata and all, to Facebook, Instagram, Twitter and other social networks.
The good news is that there are apps that let you remove and/or edit your image metadata.
For iOS, a good choice is Metadata Cut. It's free, optimized for both iPhone and iPad, and it strips out a lot of identifying metadata such as location, time, and GPS coordinates. You just open photos in your Camera Roll and extract the privacy-busting metadata. The app saves a new version of the image in your Camera Roll, which you can then share directly from within the app to Twitter, Instagram, Facebook or via email. I deleted metadata from several images and then opened them up in Photoshop on my Mac to double-check the info was gone. Everything worked as advertised. Speaking of ads, though, the free app has them in spades. You can, however, remove them for a $1 in-app purchase.
For Android users, the best option I found is Photo Editor, a free image editor that lets you edit your EXIF data and remove GPS coordinates. The app does the job, but given all its other features, it's not as intuitive or easy to use as Metadata Cut for iOS -- but it does offer more editing options. You can share your metadata-edited images on Facebook, Picasa, Twitter and other sites. Photo Editor is also advertiser-supported, though a $3 in-app purchase removes the ads.
If you're concerned about inadvertently disclosing your location by sharing images, I recommend both of these apps.